Combined surgical motor and handpiece



Sept. l, 1936.

H. A. WHITESIDE vCOMBINED SURGICAL MOTOR AND HANDPIECE original Filed July' 26, 1932 2 Sheets-Sheet 1 www bal JT.

WN SQN r H. A. WHITESIDE COMBINED lSURGICAL MOTOR AND HANDPIECE .sept 1, 1936.

`Original Filed July 26, 1932 2 Sheets-Sheet 2 INVENTORv lyon/aref /l//l'cnrll de Patented Sept. l, 1936 PATENT OFFICE COMBINED SURGICAL MOTOR AND HANDPIECE Howard A. Whiteside, New York, N. Y.

Application July 26, 1932, Serial No. 624,738 'Renewed November 27, 1935 31 Claims. (Cl. 172-36) The present invention relates to combined s'urgical motors and hand pieces and is more particularly directed toward the provision of a surgical motor and hand piece of the type wherein the motor shaft and spindle of the hand piece are hollow and the securing and releasing ,of the tool are under the control of a clutch rod which passes through the motor armature shaft and hand piece spindle.

Hand pieces wherein the coupling and uncoupling of the tool are under the control of a clutch rod passing through the spindle of the hand piece are generally known as Doriot type hand pieces, and the present invention contemplates a motorized Doriot hand piece wherein the motor for operating the tool in the hand piece is directly connected to the hand piece so that the motor and hand piece form a single instrument adapted to be held in the hand while performing surgical operations.

The principal object of the present invention is to provide a combined motor and vhand piece Another object of the invention is to provide' l a motorized hand piece of the Doriot type wherein the tool and' hand piece are effectively insulated from the electrical parts of the motor sothat there is no possibility of current leakage to shock the patient.

A further object of the invention is to provide a surgical motor having a bearing at the r'ear of the motor, preferably adjustable and oilless, which, together with the tapered bearing in the tip of the tool mayfcarry the rotating parts.

A still further object of the invention is to provide an improved end cap assembly for surgical motors and the like wherein the current supply cord or cable is secured to the end cap in an off-center position so as to permit the clutch rod of the hand piece to extend out through the center of the rear of the motor.

'A still further object of the invention is to provide a motorized hand piece of Doriot type wherein the sheath and spindle of the hand piece can be readily removed from the motor casing and armature shaft or replaced in position.

Other and further objects of the invention will appear as the description proceeds.

The accompanying drawings show, for purposes of illustrating the present invention, one of the many possible embodiments in Which the invention mayrtake form, together with modications of certain parts, it being understood that the drawings are illustrative of the invention rather than limiting the same.

In these drawings:

Figure 1 is an elevational view of a complete motorized hand piece;

Figures 2a and 2b are longitudinal sectional views through the complete motorized tool unit;

Figure 3 is a sectionalview through a modified form of construction illustrating a modified motor having a bearing for supporting the front end oi the armature shaft;

Figure 4 is a sectional view taken on the line 4 4 of Figure 3;

Figure 5 is a fragmentary sectional view through a motor having a front bearing and a hand piece having adjustment for wear;

Figure 6 is an end view of the hand piece of Figure 5;

Figure 7 is a fragmentary sectional view through a modified form of rear thrust bearing for the motor;

Figures 8a. and 8b are longitudinal sectional views through a modified form of complete motorized tool unit;

Figures 9 and 10 are, respectively,'end views of the motor unit and the hand piece unit; and

Figure 11 is a section on the line II--Il of Figure 8b.

The motorized tool unit which is illustrated in Figure 1 may be considered to consist of a motor A and a hand piece B. The hand piece is adapted to carry a tool such as a drill or grinding wheel indicated at C. The motor portion A lcontains all of the parts ordinarily found in an electric motor, and-the speed and direction of rotation of vthe motor armature may be under the control ofv a foot controller, and external resistances such as shown in my application Serial No. 113,885 PatentvNo. 1,836,350, granted December 15, 1931.

The motor A has a rigid self-supporting unitary casing I of general cylindrical shape forming a. structural part of the motor and directly supporting the field structure. This casing l0 is preferably made out of insulating material such as phenol condensation product reinforced with linen fabric. This material is hard, strong, susceptible of machining to accurate dimension, does not warp, is sanitary, water proof, possesses high insulating qualities and is capable of withstanding shock. The insulating casing forms a structural part ofthe motor as well as an insulating member to protect against stray currents or leakage. The eld structure of the motor is motor armature I1 is provided with a cylindrical type commutator I8 and a hollow steel shaft I9. The front end of the shaft I9 is provided with a collar 2|! and is threaded as indicated at 2| to receive the spindle 22 of a Doriot type hand piece B. The hand piece B may be secured to the motor b y a coupling 23. One end 24 of the coupling is threaded into the ring I5 while the other end 28 of the coupling is threaded into threads 25 in one ofthe metal sleeves 26 of a two-part sheath 21 wherein it has a longbearing as indicated. It is knurled as shown at 28a and may carry an outer covering 30 to prevent current leakage. As the armature windings are close .to the casing, the armature cannot move to the right far enough to permit the brushes to fall off'the commutator when the hand 4piece is detached.

The sheath 21 consists of a tubular metal member 26 threaded onto the coupling ring,'a second tubular metal member 29 and an insulating outer covering 30. The insulating covering 30 may abut yagainst a shoulder 3| carried by the memberL1 26 and these parts may be secured together by screws 32. The metal sheath member 29 is provided with a shoulder 33 abutting against the end of the insulating member 30 and these two parts are fastened together by screws34. The parts 26, 29 and 30 are of such length that a gap 35 appears between the adjacent ends of the metal members 26 and 29. In this manner the tip 29 of the hand piece sheath is insulated from the coupling ring 23, and the rear of the spindle. Y

VThe spindle 22 has a reduced end portion 36 threaded as indicated at 31 to receive an insulating coupling member 38 placed opposite the gap 35. 'I 'he insulating coupling member 38 has .a reduced end portion 39 threaded as'indicated at 40 to receive a spindle tip'4I. The spindle tip 4I carries a tool gripping clutch 42 and a metal plunger 43 for actuating the clutch in the usual manner. An insulating plunger 44 is carried in the insulating coupling member 38 and is interposed between the metal plunger 43 and the end 45 of a steel clutch rod 46. The clutch rod is threaded into the spindle as indicated at 41, and extends out through the motor armature shaft I9 where it is provided with a knurled head 48 as indicated. In order that the spindle parts 22, 38

and 4| may be tightly secured together, they areend cap assemblies for surgical motors and the like, Serial No. 624,739, filed July 26, 1932, patent- Bd Jan. 21, 1936, No. 2,028,176.

This brush rigging includes a disk-shaped insulating plate 50 preferably made of the same material as the casing. It has a reduced end portion as shown at 5I to telescope inside the motor casingA I0, to which it is secured, after adjustment, by screws 52. The disk carries brush boites' 53 adapted to accommodate the brushes 54,

brush springs and retaining screws 56. The outside diameter of the brush supporting disk 50 is intermediate between the inside and the outside diameter of the motor casing I0 so as to form a shoulder and at the same time accommodate an end cap 66 for the rear end of the motor. brush rigging disk 50 may, if desired, have a bridging member 51 apertured to receive the shaft, thereby providing a temporary bearing for the shaft when the end cap is removed.

This end cap is preferably made .of the same type of material and of the same outside diameter as themotor casing. The parts II), 50 and are accurately machined to provide an exceedingly close t. The end cap 60 is threaded as indicated at 6I to receive a sleeve or bearing supporting member 62. This member 62 is made of metal such as aluminum, and a tubular wood bearing 63 is carried in the bearing supporting member 62. This material forms an oilless bearing for the reduced end portion 64 of the arma- Theture shaft and the end 65 of the bearing member can be brought against a steel sleeve 65 abutting against the shoulder 66 on the armature shaft so as to provide a thrust bearing for the rear of the motor. This sleeve merely increases the bearing area against the vwood bearing and it may be omitted or a larger shoulder provided in the shaft.

'I'he adjustment of this bearing is accomplished by inserting a pin into the hole 61 in the bearing supporting member 62 and turning the bearing support in the threads 6|. A lock nut 62 is provided to lock these parts in position after they have been adjusted. The parts are preferably adjusted so that the vcombined armature shaft and spindle run freely in the bearings provided by the tube 63 and the tip 29 of the hand piece. The thrust bearing 65' serves to receive the thrust produced when the tool is pressed against the teeth or other object with which the tool is being used.

' In order to secure the end cap in position and to provide two separate circuits to conduct the current to the brush rigging and field, the brush carrying disk 5U is provided with four rearwardly extending screws, only one of which is shown at 10. These screws are clamped in position by nuts 1I threaded onto the outer ends 12 of the screws and brought against the disk 56. 'Ihe end cap 60 carries four metal inserts 13 threaded into the material of the end cap and projecting inside the motor casing as indicated. These inserts have heads 14 which enter into an annular channel or recess 15 in the end cap. Each of the inserts is provided with a nut 16 adapted to clamp the desired feed Wire in place. 'I'he nuts 1| carried by the screws 10 have rearwardly extending reduced portions 18 adapted to t the inside of the inserts 13 to align the parts, and flanged lock nuts 19 are threaded onto the ends of the screws 12, the flanges of these units overlying the heads 14 of the inserts. 'I'his way the end cap 60 and current supply cord 11 are secured to the brush carrying disk 50. This cord is preferably a four conductor rubber covered cable passed through Y the Wall of the end plate, the wires fastened under end of a bearing support 62 and a knurled finger 75 grip 85 is secured on the end of the `shaft by a lockiscrew 66. 'Ihe grip 05 and shaft are drilled as indicated at 66' so that a pin may be passed through the shaft when tightening the spindle in place. It is important that the shaft and spindle be threaded tightly together, as the motor is reversible and to prevent unthreading when adjusting the clutch rod. v

The rod 46 extends out beyond the end of the armature shaft and is supplied with the usual knurled finger grip I6. The tool C is fastened in the clutch 62 in the same manner that it is customary in Doriot type hand pieces wherein they do not form a part of the motorized tool unit. It is merely necessary to insert the shank of the tool, grasp the finger grip 65 and adjust the clutch rod by turning on the finger grip or wheel 46.

It will be noted that in this form of construction, the armature shaft and tool spindle are supported at only two points, namely in the bearing 63 and in the tapered bearing found in the tip 29. The tool and tip of the hand piece are effectively insulated against leakage of current to shoclr the patient. The entire hand piece may easily removed whenever desired.

The user can adjust the bearings without diillculty and in case it is necessary to clean or inspect the commutator cr brushes, the clutch rod l5 and finger grip 48, may be removed, the protective cover 60 taken off and the flanged nuts 'i9 removed from the screws 10. This will permit the removal of the end cap assembly so that the brush rigging may be removed by taking out the .screws 52 and the armature and spindle may be withdrawn through the rear or left end of the motor.

Inasmuch as this form of motorized hand piece is a complete unit, the entire motorized tool unit may be sterilized without danger of water getting into the interior of the motor orrronto any of the electrical connections.

Inasmuch as the magnetic flux in the field passes through the armature shaft, it is important that the armature shaft and clutch rod have as small clearance as possible so as to avoid an appreciable air gap which would change the ux distribution and relative phase angle of the current in the armature and field circuits; In order that adequate torque may b e developed on a shunt 'wound motor running on alternating current a minimum air gap between the field and armature is essential. This air gap may be about .001 inch. Should the current be accidentally turned on while the hand piece is oif, the field will attract the armature so that the stampings contact. The current consumption when the motor is stalled is insuilicient to injure the windings from overheating the same. Y Y

In the form of construction shown in Figures 3 and 4, it is contemplated that the armature shaft and tool spindle will be-supported by a 'bearingy carried in the reduced end portion I4 of the motor casing I0. As there indicated, a wood bearing 0I is placed in the bushing I6.

The front end of the armature shaft is reduced and squared as indicated at 6|. The form of coupling and sheath described above may be used,

or a longer ,coupling 23 having a shorter bearing in the sheath. The former construction is generally` preferred. Instead,l ,howeven'of having the spindle l2 identical with the spindle 22, it is, as shown in `Figure 3, shortened and threaded at 03 to receive a coupling member $4 having a squared hole l5 at the left to receive the squared end of the armature shaft. The coupling 9| may be locked to the spindle 92 by a screw 96 if desired.

'I'his type of motor having a bearing at both ends of the armature shaft may also be used with hand pieces other than the Doriot type and may or may not have adjustable thrust bearings at the rear. Where employed with a hand piece which does not have a clutch rod passing through the armature shaft, the shaft is preferably filled with a dummy clutch rod, or made solid.

Figures 5 and 6 show particularly a modified form of front bearing for the motor armature shaft together with an adjustable rear bearing for the hand piece spindle, with driving dog con' nections between the armature shaft and hand piece spindle. The motor casing I4 may be the same as formerly employed but instead of making the metal sleeve I5 of uniform diameter as indicated in Figures 1 and 3,it is cut back as indicated at I5' to accommodate a bearing |00 made of wood.

The armature shaft I0! has a shoulder |02 held against this wooden Abearing by the adjustable bearing at the rear end of the motor. The front end of the armature shaft is threaded as indicated at |03 to receive a toothed coupling |04 which is threaded against the shoulder |02 above referred to. 'I'his coupling member has driving dogs |05 adapted to cooperate with similar driving dogs |06 on the spindle |01 of the hand piece. This hand piece may have the form of construction which has been described in detail with respect to Figures 2a, and 2b, and the same reference characters are applied to corresponding parts.

When the device is to employ the hand piece spindle bearing of the form shown in Figure 5, the inside of the' coupling member 23 is threaded its entire length as indicated in |08 and two threaded rings |09 and ||0 are threaded down into this coupling ring. The ring |09 abuts against a shoulder l on the hand piece spindle |01 and is provided with a slot ||2 so that a screw driver may be passed down outside the spindle to tighten it against the shoulder. This forms an adjustable bearing to compensate for.

wear in the taper bearing in the tip of the hand piece. The threaded ring ||0 is provided with slots IIS so that this ring may be used as a lock nut to secure the other ring against movement.

'I'he teeth |05 on the end of the armature shaft are preferably designed to be at all times housed within the motor casing and the teeth |06 on the hand piece spindle are so located that they are housed at all times within the coupling member 23. In order to prevent chattering between these driving dogs, a shock absorbing device is preferably provided. In the present form of construction this is a small steel tube Il having a ypress ilt in the rear end of the hand piece spindle and projecting into the armature shaft where it is preferably split as indicated at lli. It provides a friction connection between the parts, and overrunning of the armature shaft relative to the spindle is prevented.

While the form of construction shown in Figures 5 and 6 is. especially designed for Doriot type hand pieces directly connected to surgical motors wherein the armature shaft has two bearings in the motor, it will be apparent that many featuresshown in this construction may be employed in other types of surgical outfits. The shaft bearing arrangement and driving dogs may manner similarto that shown inFigure 1.

be used in other types of surgical motors and hand. pieces and other types of surgical outfits, and the adjustable bearing in the hand piece is capable of general application.

In the form of construction illustrated in Figure '1, the metal bearing member 62 and wood bearing 63 are replaced by a bearing member 91 externally threaded at 98 to cooperate with the threads'in the end cap, as before. A locking nut 93 serves to lock these parts together after the bearing has been adjusted.

In the motorized tool unit of Figuresa and 8b, the motor unit A is somewhat similar to the motor unit A and the tool unit B is somewhat similar to the tool unit B. This tool unit employs two bearings for the armature shaft and twoI bearings for the spindle of the hand piece.

The motorcasing |20, brush carrying disk |*2|, and end cap |22 are made of insulating material. The armature shaft |23 is tubular. Its rear end is carried in a bearing |24 in the end capwhile its front end carries a socket forming terminal member |25 into which is pressed an insulating driving coupling |26. This coupling has a noncircular opening |21, as appears in Figure 9. The

front end |28 of the motor casing |20 is provided with a metal bushing |29 forming a bearing for the armature shaft and a screw threaded coupling ring |30 for the hand piece.

A disk-type commutator |3| is secured to the armature shaft, and in order to keep lubricanto the commutator, an oil thrower |32 is carried by the shaft. The brush disk |2| is secured to the casing by screws, not shown. It carries brush boxes and field connection plugs, one of each of which is shown at |33 and |34, respectively. The brush boxes carry brushes |35, and the ,field connection plugs |34 carry split pins |36. lThe brush boxes and pins fit into receptacles |31 and |38 carried by the end cap |22. The current supply wires enter the cap in an off-center hole in a The rear end of the armature shaft carries a nger grip |39. The entire motor is rreceived within a 4shield |60, preferably made of aluminum.

The hand piece B' has a one piece outer sheath |50 internally threaded at |5| toreceive a threaded coupling member |52. The exposed end of this coupling member is threaded as indicated at |53 to fit the coupling ring |36 carried by the motor. The spindle is rotatably carried in the sheath and arranged to completely. insulate the tool and sheath from the armature shaft.

The front end |54 of the spindle carries the usual clutch |55 and clutch actuating plunger |56, and is threaded at |51-to be coupled to the driving end of the spindle. This portion of the spindle is made of three tubular vparts-a metal coupling member' |58 threaded-to the clutch carrying endl |56, and pressed onto the reduced end |59 of an insulating coupling member |60. The rear end ofv this insulating coupling. member is reduced as shown at |6|, and receives a front be threaded, pinned, )r-{the rea end ofthe motor for actuating the clutch.

der |63 of the spindle and the ring |64 acts to' loci; the other ring in place.

'Ihe clutch rod is shown at |10. It is gener ally similar to the clutch rod shown in Figures 2a. and 2b, and fits closely in the armature shaft. It is, however, of considerably smaller diameter than the inside diameter of the metal coupling |62 of the spindle so as to provide air insulation between these parts. It is threaded into a metal sleeve |1| carried inside the insulation member |60, and its front end bears on a plunger |12 similar to the plunger 44. To reduce wear, this plunger |1| is made with metal ends |13 and |14 land an insulating middle portion |15. When the clutch rod is adjusted in the threaded sleeve |1l, the plunger |12 moves the plunger |56 to actuate the clutch.

The hand piece just described is adapted for use with direct connected motors and .completelyv hollow amature shaft, and an external housing supporting the motor field and carrying a bearing for the rear end of the armature shaft, -a hand piece having a sheath detachably carried at the front end of the motor casing coaxial with the armature shaft, a hand piece spindle driven by the armature shaft and having a bearing in the front end of the sheath, a tool clutch carried by the spindle, and a clutch actuating rod passing through-the armature shaft and, carried by the spindle so as to revolve with the armature and spindle, the clutch rod being accessible at the rear end of the motor for actuating the clutch.

2. In combination, an electric motor having a hollow armature shaft, and an external housing supporting the motor field and carrying a bearing for the rear end of the armature shaft,

a hand piece having a sheath detachably carried at the front end of the motor casing coaxial with the armature shaft, a hand piece spindle driven by the armature shaft and having a bearing in the front end of the sheath, a tool clutch lcarried by the spindle, and a clutch actuating rod passing through the armature shaft and carried by the spindle so as to revolve with the armature The hand` piece canv and spindle, the clutch rod being accessible at the rear end of the motor for actuating the clutch, the armature shaft extending beyond the rear bearing and carrying a collar which affords a grip to hold the shaft stationary while adjusting the clutch rod. Q

3. In combination, an electric motor having ahollow armature shaft, and an external hous- 'ing supporting the motor'eld and carrying a bearing for the rear end of 4the armature shaft, a hand piece having a sheath detachably carried at the front end of the motor casing coaxial with the armature shaft, a hand piece spindle driven by the armature shaft and having a bearing in the front end of the sheath, a tool clutch carried by the spindle, and a clutch actuating rod passing through the armature shaft and carried by 'Spi' o as to revolve with the armature e clutch rod being accessible at the the armature shaft extending beyond the rear bearing and carrying a collar which affords a grip 2,053,056 receive a pin whereby the spindle may be tightened onto the shaft.

4. In combination, an electric motor having a hollow steel amature shaft, and an external housing supporting the motor field and carrying a bearing for the rear end of the amature shaft, a hand piece having a sheath detachably carried at the front end of the motor casing coaxial with the armature shaft, a hand piece spindle driven by the armature shaft and having a bearing in the front end of the sheath, a tool clutch carried by the spindle, and a steel clutch actuating rod passing through the armature shaft and carried by the spindle so as to revolve with the armature and spindle, the clutch rod being accessible at the rear end of the motor for actuating the clutchl the air gap between the rod and shaft being narrow'whereby the flux distribution is not appreciably disturbed.

5; In combination, an electric motor having a hollow armature shaft, and an external housing supporting the motor eld and carrying a bearing for the rear-end of the armature shaft, a hand piece having a sheath detachably carried at the front end of the motor casing coaxial with the armature shaft, a hand piece spindle drivingly carried by the armature shaft and having a bearing in the front end of the sheath, the armature shaft and spindle being supported solely by said two bearings, a tool clutch carried by the spindle, and a clutch actuating rod passing through the armature shaft and carried by the spindle so as to revolve with the` armature and spindle, the ,clutch rod being accessible at the rearV end of the motor for actuating the clutch.

6.'In combination, an electric motor having a hollow armature shaft having a shoulder, and an A external housing supporting the motor ileld and carrying an axially adjustable bearing for the rear end of the armature shaft, and acting against the shoulder thereon, a hand piece having a sheath detachably carried at the front end of the motor casing coaxial with the armature shaft, a hand piece spindle driven by thearmature shaft and having a cone bearing in the front end of the sheath against which the adjustable bearing holds the spindle, a tool clutch carried by the spindle, and a` clutch actuating rod passing through thel armature shaft and carried by the spindle so as to revolve with the armature and spindle, the clutch rod being accessible at the rear end of the motor for actuating the clutch.

7. In combination, an electrcmotor having a hollow armature shaft, and an external housing supporting the motor eld and Carrying a bearing for the rear end ofthe armature shaft, a hand piece having a sheath detachably carried at the front end of the motor casing coaxial with the armature shaft,a hand piece spindle driven by the armature shaft and having a bearing in the front end of the sheath,'a plunger actuated tool clutch carried by the spindle, and a clutch actuating rod passing through thefarmature shaft and threaded into the spindle so as to revolve with the armavturel and spindle, the clutch rod being accessible at the rear end of the motor, so that it may be threaded back and forth relative to the plunger for actuating the clutch.

8. In combination, an electric motor having a hollow armature shaft, and an external housing supporting the motor field and carryinga bearing for the rear end of the armature shaft, a hand piece having a.V sheath detachably carried at the front end of the motor casing coaxial withl the armaturejshaft, a.' hand piece spindle threaded,

onto the end of the armature shaft and having a bearing in the front end of the sheath, a tool clutch carried by the spindle, and a clutch actuating rod passing through the armature shaft and threaded into the spindle so as to revolve with the armature and spindle, the clutch rod being accessible at the rear end of the motor so that it may be threaded back and forth for actuating the clutch, the spindle and shaft having devices engageable by tools so that the threaded joint therebetween may be tightened securely.

9. In combination, an electric motor having a 'hollow armature shaft, and an external housing front end of the sheath, a tool clutch carried by the spindle, and a clutch actuating rod passing through the armature shaft and carried by the spindle so as to revolve with the armature and spindle, the clutch rod being accessible at the rear end of the motor for actuating the-clutch, the spindle and sheath being provided with insulating means to prevent the leakage of current to the front end of the spindle or tool.

10.' In combination, an electric motor having a hollow armature shaft, and an external housing supporting the motor eld and carrying a bearing for the rear end of the armature shaft, a hand piece having a sheath detachably carried at the front end of the motor casing coaxial with the armature shaft, a hand piece spindle driven by the armature shaft and having a bearing in the front end of the sheath, a tool clutch carried by the spindle, a clutch actuating rod passing through the armature shaft and carried by the spindle so as to revolve with the armature and spindle, the clutch rod being accessible at the rear end of the motor for actuating the clutch, and a current supply cord carried by the rear end of the motor housing and extending out at one side of the axis of the motor.

ll. A combined motor and hand piece comprising a motor having an external housing consisting of a cup-shaped end cap carrying a bearing Ifor the rear end of the armature shaft, a cupy shaped casing to whichthe hand piece is secured,

openings, whereby th entrance of water into the combined unit is effectively prevented.

` I2. A combined motor and hand piece for surgical tools comprising a motor having an external housing consisting entirely of rigid self-sustaining insulating material to which the hand piece is secured, the bearings for the armature shaft of the motor and the spindle ofthe hand piece being water tight and the housing including a cupshaped end cap and a cup-shaped casing abutting end to end and totally enclosing all electrical parts of the motor and being characterized by the absence of openings, whereby the entrance of water intgthe combined unit is effectively prevented.

13. lfm-combination, an electric motor having a 'no llnw" .thinwalled steel shaft, a steel rod passing threaded, and a tool clutch carried by the spindle and actuated by the clutch r`od.

14. In combination, an electric motor having a hollow thin walled steel shaft, a steel rod passing through the shaft and substantially filling the hole -therein so that ux distribution is not substantially disturbed, a spindle drivingly connected to the shaft and into which the clutch rod is threaded, the exposed ends of the shaft and rod having accessible finger grips so that the shaft may be held while the rod is turned, and a tool clutch carried by the spindle and actuated by the l cmi-.ch rod. f

15. In combination, an electric motor having a hollow thin walled steel shaft, a steel rod passing through the shaft and substantially filling the hole therein so that flux distribution is not substantially disturbed, a' multiple part spindle drivingly connected to the shaft and into one part of which the clutch rod is threaded, and

`a tool clutch carried by the front part of the spindle and actuated bythe clutch rod, the front part of the spindle and the actuating mechanism of the tool clutch being insulated from the driving part of the spindle and from the clutch rod to prevent current leakage to the tool.4

16. In a combined motor and hand piece for surgical tools and the like, a hand piece sheath ried in said bearing, and a motor having an armature shaft drivingly connected to the tool spindle, said motor having a casing for supporting the hand piece sheath and an oilless adjustablewood bearing at the rear end of the motor which supports the rear end of the armature shaft, the armature shaft having a shoulder against which the bearing is adjusted.

18. In a combined motor and hand piece for surgical tools and the like, a hand piece sheath having a front cone bearing, a tool spindle havingy a tool clutch and carried in said bearing, a motor having a hollow armature shaft onto which the tool spindle is threaded, said motor having a casing for spporting the hand piece sheath and ,an` adjustable bearing at the rear end of the lmotor which supports the rear end of the amature shaft. the armature shaft having a shoulder against which the bearing is adjusted, and a clutch rod passing through the hollow armature shaft and attached to the spindie for actuating the clutch.

19. A combined motor and hand piece for surgical outfits and the like, comprising a. motor having an armature shaft, and a hand piece having a spindle drivingly connected with and carried by the amature shaft, the shaft and spindle being solely supported by a bearing at the front end of the spindle and another bearing at therear of the moto 20. A combined motor and hand piece for surgicalrioutfits and the like, comprising a motor havingxan amature shaft, and a hand piece having a spindle drivingly connected with and carried by the armature shaft, the shaft and.

spindle being solely supported by a cone bearing at the front end of the spindle and another bearing at the rear of the motor, the rear bearing being adjustable. to hold the spindle against its bearing.

21. A combined motor and hand piece for surgical outfits and the like, comprising a motor having a hollow armature shaft, a hand piece having a spindle threaded onto the armature shaft, the shaft and spindle being solely supported by a bearing at the front end of the spindle and another bearing at the rear of the motor, and a clutch rod extending through the shaft and threaded into the spindle.

22. An electric motor for combined electric motors and hand pieces, said motor comprising a iield structure, an armature, an armature shaft.

and a casing for the motor, said casing having a front end wall provided with an axially extending tubularsupport for the stationary part of the hand piece, the armature shaft extending into the tubular support and having means for detachably connecting it to the spindle of the hand piece, the shaft, when the spindle is disconnected, being supported solely by a bearing at the rear end of the motor.

23. An electric motor for combined electric motors and hand pieces, said motor comprising a neld structure, an armature, an armature shaft, anda casing for the motor, said casing having a front end wall provided with an axially extending tubular support for the stationary part of the handv piece, the armature shaft extending into the tubular support and having means for detachably connecting it to the spindle of the hand piece, the shaft, when the spindle is disconnected, being supported solely by a bearing at the rear end of the motor, the shaft having a shoulder against which the bearing is adjusted to takel rearward thrust.

.24. An electric motor for combined electric motors and hand pieces, said motor comprising a field structure, an armature, an armature shaft, and a casing for the motor, said casing having a front end wall provided with an axially extending tubular support for the stationary part of the hand piece, the armature shaft extending into the tubular support and having means for detachably connecting it'to the spindle of the .hand piece, the shaft, when the spindle is disconnected, being supported solely by a bearing at the rear end of the motor, the shaft having a shoulder against which the bearing is 'adjusted to take rearward thrust, the armature tending rearwardly, the motor having an insulating casing to which the sheath of the hand piece is securedvr and an armature shaft to which the spindle ofthe hand piece is secured and through which vthe clutch rod extends, and insulating means isolating the clutch and sheath and the armature shaft and clutch rod. n

26. A surgical tool comprising an electric motor and hand piece of the type having a sheath, a.` rotating spindle in the sheath and carrying a `tocl clutch actuated by a threaded clutch rod extending rearwardly, the motor having an insulating casing to which the sheath of the hand piece is secured and an amature shaft to whichthe spindle of the hand piece is secured and through which the clutch rod extends, and insulating means isolating the clutch and sheath and the armature shaft and clutch rod, said insulating means including a sliding insulating plunger between the end of the clutch rod and the clutch.

27. A surgical tool comprising an electric motor and hand piece of the type having a sheath, a rotating spindle in the sheath and carrying a tool clutch actuated-by a threaded clutch rod extending rearwardly, the motorhaving an insulating casing to which the sheath of the h and piece is secured and an armature shaft to which the spindle of the hand piece is secured and through which the clutch rod extends, and insulating means isolating the clutch and sheath and the amature shaft and clutch rod, said insulating means including a spindle part in the form of an insulating coupling intermediate the motor con-- nected end and the clutch carrying end of the spindle.

28. A surgical tool comprising an electric motor and'hand piece ofthe type having a sheath, a rotating spindle in the sheath and carrying a tool clutch actuated by a threaded clutch rod g extending rearwardly, the motor having an insulating casing to which the sheath of the hand piece `is secured and an armature shaft to which the spindle of the hand piece is insulatedly secured and through which the clutch `rod extends, an insulating coupling intermediate the motor connected end and the clutch carrying end of the spindle and supporting the threaded clutch rod out of Contact with the spindle, and an insulating plunger between the clutch lrod and clutch.

29. In combination, an electric motor having a hollow armature shaft and an external housing consisting entirely of rigid self-sustaining insulaiing material, a hand piece having a metal sheath detachably secured to the housing and a hollow spindle drivingly connected with the armature shaft, the spindle having a rear metal part drivingly connected to the armature shaft, a forward metal part-and insulating means between the two parts, a tool clutch in the forward part, a clutch actuating plunger slidably carried in the forward part, a slidable insulating plunger bearing on the clutch'actuating plunger, and a clutch rod extending through the armature shaft and threaded into the spindle to the rear of insulating plunger and bearing therein, the clutch rod being also insulated from the forward metal part of the spindle.

30. A' surgical tool comprising a motor unit having a tubular armature shaft carried in bearings, and a hand piece unit having a sheath detachably secured to the casing of the motor unit and detachably coupled to the armature shaft g when the. sheath is secured to the casing, and

- vented.

HOWARD A. WHITESCDE.l 

